Question

find the measure of each angle of a regular octagon

Answer 1

Here, octagon have 8 side..

so, each angle = (8-2)×180°/8 = 1080/8 = 135°

Answer 2

A octagon is a polygon with 8 sides

The sum of interior angles of any polygon is
180(n-2)
180(8-2)
180*6
1080
so,
x+x+x+x+x+x+x+x=1080
8x=1080
x=1080/8
x=135 degrees